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<br />ENGINEERS INSPECTION REPORT INSPECTOR: JGB
<br />f)FFJI, -:, Oi THE STATE ENGINEER - DIVISION OF WATER RESOURCES. DAM SAFETY BRANCH 1313 SHERMAN STREET. ROOM 818, DENVER, CO 80203, (303) 866-3581
<br />
<br />DAM NAME: GRASS VALLEY
<br />DAM 10: 390108 YRComp/:
<br />CLASS: 1
<br />DlV: 5 WD:
<br />EPP: 11'/26/2002
<br />
<br />CURRENT RESTR/CTlO - NONE -
<br />
<br />OWNER: SILT WATER CONSERVANCY DISTRICT
<br />ADDRESS: P.O. BOX 216
<br />SILT CO 81652
<br />
<br /> T: 050S R: 092r:JW S: 24 COUNrt : GARFIELD DATE OF INSPEClION: 4/11/2003
<br />1892 DAM HEIGHT(FT): 61.0 SPILLWAY WIDTH(FT): 15.0 PREVIOUS INSPECTION: 8/12/2002
<br /> DAM LENGTH(FT): 800.0 SPILLWAY CAPACITY(CFS): 542.0 CAPACITYIAF): 5806.0
<br />39 CRESTWIOlH(FT): 20.0 FREEBOARO (Fl): 5.0 SURFACE AREA(AC}: 320.0
<br /> CRESTELEV(FT): 6407.0 DRAINAGE AREA lAC.): 1402.0 OUTLET INSPECTEO: 4/11/2003
<br />
<br />CONTACT NAME:
<br />CONTACT PHONE:
<br />
<br />SCOTT DODERO
<br />(970) 876-2393
<br />
<br />INSPECTION PARTY:
<br />REPRESENTING:
<br />FIELD
<br />CONDITIONS
<br />OBSERVED
<br />
<br />Scott Dodero 20nd others
<br />Silt Water Conservancv District
<br />
<br />Bruce MaNin (dye testino\
<br />Western Enaineers
<br />
<br />Jim lemon - Water Commissioner
<br />John G. Blair - Dam Safetv Enaineer
<br />
<br />6.5
<br />~
<br />
<br />1.5
<br />n
<br />
<br />WATER LEVEL: BELOW DAM CREST
<br />GROUND MOISlURE caMeroON: DRY
<br />
<br />FT.
<br />WET
<br />
<br />8elow Spillway
<br />n SNOWCOVER
<br />
<br />FT.
<br />OTHER
<br />
<br />GAGE ROO REAOlKG
<br />
<br />DIRECTIONS: MARK AN X FOR CONDITIONS FOUND AND UNDERLINE 'NaRDS THAT APPLY
<br />
<br />
<br />PROBLEMS NOTED D(OlNONE ~ (1)RIPRAP ~ MISSING SPARSE, DISPLACED, Vv'EATHERED 0 (2) WAve EROSION. 'MTH SCARPS
<br />O(3)CRACKS WfTHDISPLACEMENT D(4)SINKHOLE 0 (5) APPEARS TOO STEEP 0(6) DEPRESSIONS OR BULGES ~ (7)SL.lDES
<br />D(B)CONCRETEFACING- HOLES, CRACKS, DISPLACED, UNDERMINED 0 (9)OTH~R
<br />
<br />(2): Old slide inriprap at.gage 25 result.ing from 1918 failiJre is not visible.
<br />; ,;>,--.' '. - .~" '~"\," "
<br />-"~.\!",;' ""'1_,; '\c,};~:,::,>'"::..,:.,,,:, ,,~.'
<br />
<br />(.1 ): Missing ~only in far east groin.
<br />dtie:to:reservorr'level ,~.-;,.:>\ "'"
<br />
<br />~ <~~i~~'<f;:r~" ,."\ ~
<br />'/'k!"'t. - ;/~'-":l:t:,'~"'" "i."
<br />
<br />;1~;;' >L' ..~: ~f;' >;.
<br />
<br />'''--'-
<br />
<br />'.;''\--'.,'."~,.
<br />
<br />
<br />PROBLEMS NOTED 0(10) NONE 0(1 t) RUT OR PUDDLES 0 (12) EROSION 0 (13) CRACKS - VV1TH DISPLACEMENT 0(14) SINKHOLES
<br />0(15) NOT \NIDE ENOUGH ~ (16) LOW AREA 0(17) MISAliGNMENT 0(18) IMPROPER SURFACE DRAINAGE 0 (19) OTHER
<br />Crest is. well graded and unifonn. It is gradually lower in itscenter.by 1'. Survey shows no change
<br />
<br />
<br />PROBLEMS NOTED 0(20) NONE 0 (21) LIVESTOCK DAMAGE 0 (22) EROSION OR GUlliES 0 (23) CRACKS. VV1TH DISPLACEMENT 0 (24) SINKHOle
<br />0(25) APPEARS TOO STeEP ~ (26) DEPRESSIONS OR BULGES 0 (27) SLIDE 0 (2B) SOFT AREAS 0 (29) OTHER
<br />
<br />. Historic.crack not visible and probing showed.no signs of a crack.. It may have sealed.itselfwith recent wet
<br />weather. The rebar stakes below monument #4 were 1.4' apart - no significant change (26): Const spoils
<br />above outlet creates. bulge - no change . .
<br />
<br />0:
<br />.
<br />.c
<br />'"
<br />.
<br />f
<br />PROBLEMS NOTED 0(30) NONE 0(31) SATURATED EMBANKMENT AREA 0 (32) SEEPAGE EXITS O~ EMBANKMENT C
<br />
<br />~ (33) SEEPAGE EXITS AT POINT SOURCE 0 (34) SEEPAGE AREA AT TOE ~ (35) FLOW ADJACENT TO OUTlET 0 (36) SEEPAGE INCREASED J MUDDY ~
<br />DRAlNOUTFALlSSEEN ~No DYes ShONklcationofdminsCflsketchandiodlcale 0(37) FLOW INCREASED I MUDDY o (3B) DRAIN DRYI OBSTRUCTED ctl
<br />amount aJd quality of discharge. a
<br />~(39) OTHER Wet area ,@ toe' east of outlet -,5' x 3', .3' ~eep =
<br />.S
<br />..
<br />...
<br />'.
<br />~
<br />.
<br />.
<br />'"
<br />
<br /><:SF;~ "
<br />
<br />(33) & (35): Outlet tunnel seepage - point 1 & 2 approx. O.5.gpm; point 3 = 2;18 gpm; point 4 =16gpm. These
<br />are consistant with past readings for similar res. elev:. .See.att3ched summary & graphs. Dye test performed,
<br />see details with attached picture' .
<br />
<br />PROBLEMS NOTED 0(40) NONE 0(41) NO OUTLET FOUND 0(42) POOR OPERATING ACCESS 0(43) INOPERABLE
<br />
<br />0(44) UPSTREAM OR DO'hNSTREAM STRUCTURE DETERIORATED (45) OUTlET OPERATED DURING INSPECTION DYES ~NO
<br />INTERIOR INSPECTED 0(120) NO ~ (121)YES 0(46) CONDUIT DETERIORATED OR COLLAPSED 0(47) JOINTS DISPLACED ~(48) VAL.VE ~EAKAGE
<br />
<br />~(49)OTHER a~ut. @spillway pass seepage into outlet tUrin,el
<br />
<br />(45):.Outlet exercised. yesterday and lubricated last fall. (121): Tunnel Inspected with seepage,measureme~ts -
<br />No significant. change: .. . .:..,.. ,.....'..,:;..,.,. .':.
<br />,.'. "" "." ,.."' '-., ~. '. _c."" ~;.- ',j
<br />
<br />>.':
<br />
<br />PROBLEMS NOTED 0 (SO) NONE 0 (51) NO EMERGENCY SPILLWAY FOUND 0 (52) EROSION WITH BACKCUTTING 0 (53) CRACK. 'MTH DISPLACEMENT
<br />0(54) APPEARS TO BE STRUCTURAlLY INADEQUATE 0 (55) APPEARS TOO SMALL 0 (56) INADEQUATE FREEBOARD 0 (57) FLOW OBSTRUCTED
<br />~(56) CONCRETE OETERIORATED J UNDERMINED ~(59l OTHER Spillway'seepage from'cracks in' Concrete
<br />'j'" n '.'" " ....n ",,,,,,,P.
<br />(58): Deterioration in spillway noor maybe slightly worse. See details with.photo:'(59): No visual change in
<br />the seepage, but now measured more -see details with photo and summary and graph. Spillway channel was
<br />clea'iled,6ut since last ear.
<br />
<br />50.5
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<br />
<br />Conditions
<br />Observed
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<br />'x' '
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<br />GAP
<br />o C 0
<br />D C 0
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